Some of the actions provided with vRealize Operations Manager require the virtual machines to shut down or power off, depending on the configuration of the target machines, to run the actions. You should understand the impact of the Power Off Allowed option before running the actions so that you select the best options for your target virtual machines.

Power Off and Shut Down

The actions that you can run on your vCenter Server instances include actions that shut down virtual machines and actions that power off virtual machines. It also includes actions where the virtual machine must be in a powered off state to complete the action. Whether the virtual machine is shut down or powered off depends on how it is configured and what options you select when you run the action.

The shut down action shuts down the guest operating system and then powers off the virtual machine. To shut down a virtual machine from vRealize Operations Manager, the VMware Tools must be installed and running on the target objects.

The power off action turns the virtual machine off without regard for the state of the guest operating system. In this case, if the virtual machine is running applications, your user could lose data. After the action is finished, for example, modifying the CPU count, the virtual machine is returned to the power state it was in when the action began.

Power Off Allowed and VMware Tools

For the actions where you are increasing the CPU count or the amount of memory on a virtual machine, some operating systems support the actions if the Hot Plug is configured on the virtual machine, but for other operating systems, the virtual machine must be in a powered off state to change the configuration. To accommodate this need where the VMware Tools are not running, the Set CPU Count, Set Memory, and Set CPU Count and Memory actions include the Power Off Allowed option.

If you select Power Off Allowed, and the machine is running, the action verifies whether VMware Tools is installed and running.

  • If VMware Tools are installed and running, the virtual machine is shut down before completing the action.

  • If VMware Tools are not running or not installed, the virtual machine is powered off without regard for the state of the operating system.

If you do not select Power Off Allowed and you are decreasing the CPU count or memory, or the hot plug is not enabled for increasing the CPU count or memory, the action does not run and the failure is reported in Recent Tasks.

Power Off Allowed When Changing CPU Count or Memory

When you run the actions that change the CPU count and the amount of memory, you must consider several factors to determine if you want to use the Power Off Allowed option. These factors include whether you are increasing or decreasing the CPU or memory and whether the target virtual machines are powered on. If you increasing the CPU or memory values, whether hot plug is enabled also affects how you apply the option when you run the action.

How you use Power Off Allowed when you are decreasing the CPU count or the amount of memory depends on the power state of the target virtual machines.

Table 1. Decreasing CPU Count and Memory Behavior Based On Options

Virtual Machine Power State

Power Off Allowed Selected

Results

On

Yes

If VMware Tools is installed and running, the action shuts down the virtual machine, decreases the CPU or memory, and powers the machine back on.

If VMware Tools is not installed, the action powers off the virtual machine, decreases the CPU or memory, and powers the machine back on.

On

No

The action does not run on the virtual machine.

Off

Not applicable. The virtual machine is powered off.

The action decreases the value and leaves the virtual machine in a powered off state.

How you use Power Off Allowed when you are increasing the CPU count or the amount of memory depends on several factors, including the state of the target virtual machine and whether hot plug is enabled. Use the following information to determine which scenario applies to your target objects.

If you are increasing the CPU count, you must consider the power state of the virtual machine and whether CPU Hot Plug is enabled when determining whether to apply Power Off Allowed.

Table 2. Increasing CPU Count Behavior.

Virtual Machine Power State

CPU Hot Plug Enabled

Power Off Allowed Selected

Results

On

Yes

No

The action increases the CPU count to the specified amount.

On

No

Yes

If VMware Tools is installed and running, the action shuts down the virtual machine, increases the CPU count, and powers the machine back on.

If VMware Tools is not installed, the action powers off the virtual machine, increases the CPU count, and powers the machine back on.

Off

Not applicable. The virtual machine is powered powered off.

Not required.

The action increases the CPU count to the specified amount.

If you are increasing the memory, you must consider the power state of the virtual machine, whether Memory Hot Plug is enabled, and whether there is a Hot Memory Limit when determining how to apply Power Off Allowed.

Table 3. Increasing Memory Amount Behavior

Virtual Machine Power State

Memory Hot Plug Enabled

Hot Memory Limit

Power Off Allowed Selected

Results

On

Yes

New memory value ≤ hot memory limit

No

The action increases the memory the specified amount.

On

Yes

New memory value > hot memory limit

Yes

If VMware Tools is installed and running, the action shuts down the virtual machine, increases the memory, and powers the machine back on.

If VMware Tools is not installed, the action powers off the virtual machine, increases the memory, and powers the machine back on.

On

No

Not applicable. The hot plug is not enabled.

Yes

If VMware Tools is installed and running, the action shuts down the virtual machine, increases the memory, and powers the machine back on.

If VMware Tools is not installed, the action powers off the virtual machine, increases the memory, and powers the machine back on.

Off

Not applicable. The virtual machine is powered off.

Not applicable.

Not required

The action increases the memory the specified amount.